Electrically heated steam reforming reactor

ABSTRACT

What has been achieved by this invention is a method and design of providing high temperature heat for an endothermic gasifier without combustion using electrical resistance immersion heating element technology. Further, these elements could be heated by three phase electrical power; thus, minimizing the number of electrical leads emerging from the top of the heating elements. 
     This invention solves the difficulty of designing the steam/CO 2  reforming reactor with a large number of densely packed heating elements and the syngas heat recuperator into one reactor. This is done to avoid the extremely hot syngas leaving the reactor from melting the downstream metal fittings carrying the reactor product gases to the downstream piping process.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to U.S. ProvisionalPatent Application Ser. No. 62/103,246, filed Jan. 14, 2015,incorporated herein by reference.

FIELD OF INVENTION

Various embodiments of the present invention pertain to a hightemperature gasification reactor, and in some embodiments such a reactorincluding steam/CO₂ reforming, and in still further embodiments withoutthe use of combustion.

BACKGROUND OF INVENTION

One problem with gasification is poor conversion because thetemperatures were simply not high enough to destroy the complex organiccompounds and avoid soot and dioxin formation, even in situations wherethere is partial oxidation with oxygen or even air burning some of thefeedstock to produce higher temperatures. Further, there may not beenough heat available in the gasification sections where the syngas wasburned to provide heat for the endothermic gasifier to achieve thetemperatures needed. As a result gasification has suffered from failedapplications, poor economics and general criticism throughout the worldas a being an “incinerator in disguise.”

Various embodiments of the present invention provide improvements in theheating of gasifier sections that are novel and unobvious.

SUMMARY OF THE INVENTION

This invention in some embodiments relates to a chemical reactor designsystem in which a new method of electrical heating is disclosed topermit the reactor to operate as a high temperature gasificationreactor, specifically steam/CO₂ reactor reforming, to achieve the veryhigh temperatures needed without the use of combustion or oxygen-blowncombustion and achieving near complete conversion to achievethermodynamic equilibrium composition in the reforming chemistry with ahydrogen rich syngas with little CO₂ or N₂ diluent.

What has been achieved by some embodiments this invention is a methodand design of providing the required high temperature heat for thegasifier without combustion using electrical resistance immersionheating element technology. Earlier reforming reactors were electricallyheated by glass-like heating elements that were very fragile. They wereeven more brittle once they were heated, and could not easily be removedand replaced in the field.

One embodiment includes a gasifier having heating element technologythat involves swaging high resistant nichrome wire in a ceramic matrixunder pressure within a high-temperature super alloy tube. Further,these elements could be heated by three phase electrical power; thus,minimizing the number of electrical leads emerging from the top of theheating elements.

Some embodiments address the difficulty of designing the steam reformingreactor with the heating elements and the syngas recuperator into onereactor. This is done in some embodiments to keep the extremely hightemperature syngas leaving the reactor from melting the downstream metalfittings carrying the reactor product gases to the downstream pipingprocess.

Yet another embodiment of the present invention pertains to the use ofturbulence-enhancing features that provide turbulence into the freestream of the main flow in order to better control the convectiveboundary layer and achieve increased heat transfer.

Yet other embodiments use a novel electrical lead multi-layered busdesign that permits an efficient and simple and electrical leadarrangement with minimal lead length.

Yet further embodiments of the present invention include monitoring thetemperature of individual leads with an IR camera to detect variationsin lead temperature, and further including an electrical control systemto vary the application of electrical power and manipulate anytemperature variations.

It will be appreciated that the various apparatus and methods describedin this summary section, as well as elsewhere in this application, canbe expressed as a large number of different combinations andsubcombinations. All such useful, novel, and inventive combinations andsubcombinations are contemplated herein, it being recognized that theexplicit expression of each of these combinations is unnecessary.

BRIEF DESCRIPTION OF DRAWINGS

Some of the figures shown herein may include dimensions. Further, someof the figures shown herein may have been created from scaled drawingsor from photographs that are scalable. It is understood that suchdimensions, or the relative scaling within a figure, are by way ofexample, and not to be construed as limiting.

FIG. 1A is a cross sectional representation of an insulated reactor withheating elements inserted downward from the top lid into two flow zones,one with upward flow in the outer annulus and then a flow reversal todownflow in the center of the annulus with flow leaving at the bottom asthe reactor exit. Then in both annular flow regions, the flow isenhanced by turbulence-creating features.

FIG. 1B is an enlargement of the top portion of the apparatus of FIG.1A.

FIG. 1C is an enlargement of a portion of the bottom of the apparatus ofFIG. 1A.

FIG. 1D is an external view of the apparatus of FIG. 1A.

FIG. 1E is a cross sectional view of the apparatus of FIG. 1A as lookingdown along section A-A of FIG. 1A.

FIG. 2 is a cross sectional representation perpendicular to thecenterline of the reactor of FIG. 1A which shows how these heatingelements are arranged in the two annular regions.

FIG. 3A shows another embodiment in which a high temperature radiationobject is used to radiate exit heat on to a fin cylindrical heatexchanger around the outside.

FIG. 3B is an enlargement of the bottom portion of the apparatus of FIG.3A.

FIG. 4A shows a manifold arrangement according to another embodiment ofthe present invention where the feed gases are provided into the outerannulus and the hot exit gas leaving the bottom of the reactor in thecenter. This manifold design preferably provides a counterflowcylindrical tube heat exchanger as a recuperator.

FIG. 4B is an enlargement of a portion of the bottom of the apparatus ofFIG. 4A.

FIG. 5A shows top plan views and side cross sectional elevational viewsaccording to another embodiment of a reactor with a coil heat.

FIG. 5B shows a cross section of the apparatus of FIG. 5A looking downat line B-B, showing a coil and a thermal radiating block centrallylocated in this coil.

ELEMENT NUMBERING

The following is a list of element numbers and at least one noun used todescribe that element. It is understood that none of the embodimentsdisclosed herein are limited to these nouns, and these element numberscan further include other words that would be understood by a person ofordinary skill reading and reviewing this disclosure in its entirety.

1 reformer 2 wires 4 screw 6 busbar 8 thermocouple 10 vertical immersionelement 12 sanitary union 14 busbar 15 reactor 16 top flange 19 top 18gaskets 20 ceramic 22 flow annulus 24 tension wrap 26 wire surface 28turbulence trips 30 screen 32 fiberglass insulation 34 reactor metal 36bottom mounting plate 38 insulation 40 mounting screws 42 mounting holes50 concentric tubes 60 heating elements; annulus 64 heating elements 66busbar 300 baffle 301 diverted flow 302 exit 306 pipe 308 flange 309feed flow; flow input streams 310 elbow 311 flow outlet streams 312flange 314 insulation plates 316 feed ports 318 inlet flows; flow inputstreams 320 flange pairs 322 port 324 flow outlet streams 326 exit gas330 plenum box 399 reactor reformer 400 annular tube 401 heat exchanger402 gas 404 square wrap 406 square wrap 408 plate mixer 410 exteriorceramic blanket 412 reactor ball 414 flow 416 pipe 418 can 420 solidbody; heat sink 422 fasteners 423 fins 424 ceramic 426 ceramicinsulation 428 base 430 base plate 432 gas flow 434 pipe 436 tangentialentrance 438 bottom annular plenum region 440 spiral gaskets 442 O-ring444 flow 446 annular space 500 thermocouples 504 heating elements 510annular flow region 514 entrance tube 518 transition points; radiuselbow; reactor vessel 520 body 522 heat exchanger 523 exchange plenum524 bulkhead fitting 526 piping 530 port 532 annular tube 534 heatblanket 536 shape 538 reactor 542 bolting 544 rim clamps 546 lid 548thermocouples 550 reactor top

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates. At least one embodiment of the present inventionwill be described and shown, and this application may show and/ordescribe other embodiments of the present invention.

It is understood that any reference to “the invention” is a reference toan embodiment of a family of inventions, with no single embodimentincluding an apparatus, process, or composition that should be includedin all embodiments, unless otherwise explicitly stated. Further,although there may be discussion with regards to “advantages” providedby some embodiments of the present invention, it is understood that yetother embodiments may not include those same advantages, or may includeyet different advantages. Any advantages described herein are not to beconstrued as limiting to any of the claims. The usage of wordsindicating preference, such as “preferably,” refers to features andaspects that are present in at least one embodiment, but which areoptional for some embodiments.

Although various specific quantities (spatial dimensions, temperatures,pressures, times, force, resistance, current, voltage, concentrations,wavelengths, frequencies, heat transfer coefficients, dimensionlessparameters, etc.) may be stated herein, such specific quantities arepresented as examples only, and further, unless otherwise explicitlynoted, are approximate values, and should be considered as if the word“about” prefaced each quantity. Further, with discussion pertaining to aspecific composition of matter, that description is by example only, anddoes not limit the applicability of other species of that composition,nor does it limit the applicability of other compositions unrelated tothe cited composition.

What will be shown and described herein, along with various embodimentsof the present invention, is discussion of one or more tests or analysesthat were performed. It is understood that such examples are by way ofexample only, and are not to be construed as being limitations on anyembodiment of the present invention. Further, it is understood thatembodiments of the present invention are not necessarily limited to ordescribed by the mathematical analysis presented herein.

Various references may be made to one or more processes, algorithms,operational methods, or logic, accompanied by a diagram showing suchorganized in a particular sequence. It is understood that the order ofsuch a sequence is by example only, and is not intended to be limitingon any embodiment of the invention.

Various references may be made to one or more methods of manufacturing.It is understood that these are by way of example only, and variousembodiments of the invention can be fabricated in a wide variety ofways, such as by casting, centering, welding, electrodischargemachining, milling, as examples. Further, various other embodiment maybe fabricated by any of the various additive manufacturing methods, someof which are referred to 3-D printing.

What will be shown and described herein are one or more functionalrelationships among variables. Specific nomenclature for the variablesmay be provided, although some relationships may include variables thatwill be recognized by persons of ordinary skill in the art for theirmeaning. For example, “t” could be representative of temperature ortime, as would be readily apparent by their usage. However, it isfurther recognized that such functional relationships can be expressedin a variety of equivalents using standard techniques of mathematicalanalysis (for instance, the relationship F=ma is equivalent to therelationship F/a=m). Further, in those embodiments in which functionalrelationships are implemented in an algorithm or computer software, itis understood that an algorithm-implemented variable can correspond to avariable shown herein, with this correspondence including a scalingfactor, control system gain, noise filter, or the like.

In FIG. 1 are shown various views of a preferred embodiment that is a 7ton per day electrically heated steam reformer 1 that has a number ofvertical immersion elements 10 and a flow annulus 22 in the center toreverse the flow direction from in to out that achieves mixing andgenerates turbulence to enhance the heat transfer, so that the reactorvessel preferably remains under 12 ft in height, although otherembodiments of the present invention contemplate reactor vessels of anyheight. At the bottom of the reactor is a plurality of concentric tubes50 that feed the reactor and remove the hot syngas while the exchangingbetween the two so that the exit syngas is not too hot for downstreampiping.

The heating elements (such as those sold by Chromalox and Watlow, asexamples) are mounted in the top flange 16 by means of a sanitary union12 so they can be easily removed and pulled out even if they haveblisters and misshapen diameter after service hours. Around thecircumference is a triple stack of busbars 6 into which the wires 2 fromthe elements can be placed, captured by locking screw 4 and be poweredelectrically. Down the center is inserted a thermocouple 8 for measuringthe temperature of the elements in the center of the reactor.

The reactor is lined on the inside with a foam ceramic 20. Theinsulation also contains a square wire surface 26 to trip the boundarylayer and increase the heat transfer from the heating element. There arealso square wire turbulence trips 28 located on both sides of theannulus 22. Note that boundary layer tripping devices 26 and 28 arespaced apart along the direction of flow, which provides turbulentmixing with minimal obstruction to the overall flowpath. Further, it isunderstood that the boundary layer tripping features can be of any shapeand orientation, with square cross sectional wires being just oneexample. The elements could also use a “tension wrap” 24 to furtherextend the heat transfer surface for more heat transfer.

As the gases enter into the annulus there is placed a screen 30 thatgenerates turbulence to enhance the heat transfer. Because the reactoris insulated by foam and ceramic 20 on the inside, the reactor metal 34does not have to involve an exotic alloy. On the outside of the reactorvessel is fiberglass or other suitable insulation 32 to prevent aburning hazard.

The flange lid on the top of the reactor 15 is sealed by means ofgaskets 18 (such as gaskets provided under the name Spirotallic). At thebottom of the reactor is the plate 36 on which the annulus 22 in thereactor vessel is mounted and welded. The bottom plate 36 has insulationfoam 38 to keep the temperatures at a reasonable level, and is attachedby means of mounting screws 40. This plate also has mounting holes 42for mounting the reactor to the frame.

The gas fed to the reactor enters by the concentric tubes 50 (seesection B-B) which feeds the gas up the outside of the annulus 22,around the top 19, down to the center and exiting it at the center ofthe concentric tube 50.

The arrangement of the heating elements at the top of the reactor servesboth the outer annular flow region 22 and the inner annular flow region9 as is shown in a view from the top in FIG. 2. There is a power busbar66 just above the reactor top 16 where the power is fed to 12 heatingelements 60. Here the inner ring 4 of elements 12 draws 24 Amps and theouter ring of eight elements 12 draws 48 Amps. At the outside ring thereis a pair of busbars 14 and 66 for distributing the power to the 16heating elements 64, with each of the busbars handling 48 amps each. Theelement power is about 5 kW 480 vac WYE with a magnesium oxide internalceramic. The common mode voltage to ground is 277 vac in thisarrangement and the heat flux is 18 W per square inch for a heatedlength of 88 inches. The total power for all 28 elements is 140 kW.Throughout the cross-section there are seven thermocouples 8 placed downnear the heating elements to get a view of the temperature distribution.Their placement is shown as the black dots in FIG. 2.

FIG. 3 show a reactor reformer 399 according to yet another embodimentof the present invention. Device 399 includes a heat exchanger 401 atthe bottom of the reactor using a reradiating solid body 420. The gasflow 432 enters the bottom of this reactor through pipe 434 thatincludes a tangential entry 436 which creates the swirl flow in theplenum region 438 improving the heat transfer on the fins 423. Thisinlet flow is preheated by the heat transfer from the fins 423 thatwarms the flow entering the annular space 446 of the reactor 412.Electrical heating elements 402 further heat the gas as enhanced byperforated plate mixer 408 as well as the turbulence created by theturbulence-generating features and boundary layer tripping devices 406on both sides of the annular tube 400. Gas turbulence is created bysquare wraps 404 and 406.

The flow in the annulus on the outside of the annular tube 400 flowsover the top of this annular tube and down the center as flow 444flowing over the reradiating body 420 and its base 428. Heated body 420at operating conditions is a glowing yellow-orange hot surface radiatingoutward onto the surface of the fins 423. This radiating body 420 sitsin the reactor exit flow entering the cylindrical can 418. Heat fromflowpath 444 is conducted and convected into radiating body 420, whichradiates and conducts heat onto fins 423. Thus, these reactor exitgases, having been cooled by the reradiating body and the fins 423,leaves this bottom can through pipe 416 as a cooled flow 414. Thisplenum chamber 438 is bolted to the reactor 412 that has internal foamceramic insulation 426 as well as exterior ceramic blanket 410 on top ofthe reactor wall 412 to avoid skin burning and is sealed with the spiralgaskets for 440 and a small Indium O-ring 442. This bottom plenum isinsulated by ceramic 424 on the sides and the bottom which is held on byscrews 422 into this plate 428 which is welded to the bottom base-plate430. The reradiating body 420 is preferably composed of four sectionsthat can be individually removed through the port above so they can becleaned and replaced.

FIG. 4 describes a more detailed reactor bottom design for feeding gasto the reactor and extracting the syngas product. In FIG. 4 the reactantgases 309 flow in through flange 308. The flow from the inlet pipe exit302 impacts baffle 300 where the diverted flow 301 is a mixed into smallvortices so that the flow distribution in the bottom plenum box 330 moreequally feeds the four annular feed ports 316 producing inlet flows 318.The product syngas leaves the reactor at flow 324 in the single largerport 322 and leaves from the bottom plenum in pipe 306 with the smallerpipe inside. This concentric arrangement serves as a countercurrent heatexchanger to recover the exit heat and use it to preheat the feed flow309. The flange arrangement 308 permits the gases in this larger pipe totravel around elbow 310 as flow 311 to exit through flange 312.

There are insulation plates 314 inserted in the bottom plenum 330 nextto the reactor bottom and plates 312 at the exit pipes above the plenum330. There are four flange pairs 320 serving flow entering at 318 andthe single flange for the exit gas 326 that are accessible with clampsfor their seal so that the bottom section can be easily removed forcleaning and installation.

Yet another embodiment of the present invention is shown in FIGS. 5A and5B, which show a cross section of a 1/10 scale reactor used in a pilotplant to test the concept of an entrance tube 514 with coiled tube heatexchanger 522 with a ceramic reradiating body 520 located at the tubecoil center. The very hot syngas enters the coil heat exchanger throughport 530 located in this heat exchanger bottom plenum 523. Long radiuselbows are used at the two transition points 518 entering and leavingthe coiled heat exchanger. The feed gases preheated by the coiled heatexchanger 522 (also detailed in FIG. 5B) enter the annular flow region510 through a welded long radius elbow 518. A high alloy annular tube532 is welded to the base of the reactor that is the top of the heatexchanger plenum 523. The exit gases leave the bottom plenum 523 throughbulkhead fitting 524 and exit piping 526.

The reactor vessel 518 is insulated from the inside with a foam aluminainsert 536 cast into the final shape and preferably surrounded by heatblanket 534 (such as a blanket comprises Kaowool) and a cast foaminsulating lid 538 to the reactor. The reactor top 550 has a clamp onstainless lid 546 using steel rim clamps 544 and bolting 542. Throughthe top of this reactor lid are thermocouples 548 going down into theannular flow region as well as thermocouples 500 going down into thecenter portion of the reactor. The lid is shown with four immersionheating elements 504 attached to the top of the lid by a sanitaryclamp-on fitting.

One embodiment of the present invention is presented in an example thatinvolves validating the electrical heating elements performance using acomputational heat transfer model that includes the turbulence promotersshown in FIG. 1 in the two flow passages of the outer annulus and in thecenter annular core as well as the flow paths shown in the bottom heatrecuperator shown in FIG. 3.

The Table 1 below shows the computational heat transfer model results inconsideration of the apparatus of FIG. 4 for each of the flow inputstreams 309 and 318, together with the flow outlet streams 324 and 311.The electrical heating elements 60 and 64 shown placed downward throughthe lid shown in FIG. 2 are in two groups: first group 64 placed in theouter annular flow region 8 and totaling 16 elements drawing a currentof 96 amps, and the second group 60 of 12 elements drawing 72 ampsplaced in the central region of the annulus 9. The total heatingcapacity of these groups of elements is 144 kWe. The fixed constants forthe calculations are given in the top portion of this table involving 14rows.

For comparison the heat transfer model predicts that the heat transferof 504.11 kWe is possible given the gas mass flow of 3500 lbs/hr shownin the row labeled “Gas Flow In”. In the rows below are shown each ofthe steps of the calculations down to the the 2^(nd) row from the bottomshowing the maximum heat transfer possible of 504.11.

If all the turbulence generator strakes were removed, the total maximumheat transfer achieved is predicted to be 279.75 kWe—nearly double theelectrical capacity of the elements of 144 kWe.

Various aspects of different embodiments of the present invention areexpressed in paragraph X1 as follows:

One aspect of the present invention pertains to a method forgasification. The method preferably includes flowing a stream of a firsthydrocarbon gas from an inlet at the bottom of a first plenum toward atop outlet. The method preferably includes electrically heating theflowing first gas along the axial length of the first plenum. The methodpreferably includes flowing the heated gas from the top outlet to a topinlet of a second plenum and toward a bottom outlet. The methodpreferably includes heating the flowing gas along the axial length ofthe second plenum.

Yet other embodiments pertain to the previous statement X1, which iscombined with one or more of the following other aspects.

The method preferably includes converting the first hydrocarbon gas to asyngas by said heating in at least one of the plenums and removing thesyngas from the bottom outlet.

Wherein the first plenum is of any shape, and the second plenum is ofany shape.

Where in the second plenum is located within the first plenum.

Which further comprises first flowing the stream of the firsthydrocarbon gas from an entrance of a first plenum toward the bottominlet.

Which further comprises transferring heat from the syngas proximate thebottom outlet to the first gas in the first plenum.

Wherein the first plenum includes a plurality of heat transfer fins.

Which further comprises flowing the removed syngas from the bottomoutlet over a heat sink.

Wherein the heat sink is a radiative heat sink.

Wherein the heat sink is aerodynamically shaped to minimize resistanceto the flow of the syngas.

Which further comprises transferring heat from the heat sink to thefirst hydrocarbon gas; wherein said transferring heat is by radiationand convection; wherein said transferring heat is substantially byradiation.

Wherein said electrically heating in the first plenum is by a pluralityof resistive heating elements each extending along substantially theentire axial length of the first plenum.

Wherein each of the resistive heating elements is substantially linear.

Wherein each of the resistive heating elements has two ends and whichfurther comprises supporting each element at only one end.

Wherein the first hydrocarbon gas includes steam.

Wherein the syngas includes substantial hydrogen.

Wherein the first plenum surrounds the second plenum.

Which further comprises thermally insulating the outer diameter of thefirst plenum.

Wherein the outer wall of said first plenum includes a ceramicinsulator.

Wherein at least one of the inner or outer cylindrical walls of saidfirst plenum includes a plurality of aerodynamic strakes protruding intothe annular flowpath.

Which further comprises generating turbulence by the strakes.

Which further comprises generating vortices by the strakes during saidflowing the heated gas toward the top outlet.

Wherein a wall of the second plenum includes a plurality of aerodynamicstrakes protruding into the flowpath.

Which further comprises generating vortices by the strakes during saidflowing the heated gas toward the bottom outlet.

Which further comprises repeatedly tripping the boundary layer duringsaid flowing a stream.

Which further comprises repeatedly tripping the boundary layer duringsaid flowing the heated gas.

TABLE 1 STEAM REFORMER REACTOR ZONE HEAT TRANSFER ANALYSIS Wellhead GasNom = 25 wet tpd Fee Temperature in = 300 ° F. Wellhead Gas Feedrate =5724 lbs/hr Feedrate in tone = 68.688 Total Process Heat Need = 2.388 mmBTU/hr Total Process Heat Need = 699.7 kW Total Process Heat NeedOutside = 2.388 mm BTU/hr 50% Process Heat Need = 699.68 kW Number of 7tpd size reactors = 9.81 5.14 kW/element Number of elements = 28 144.05kW total element surface area = 8996.16 in2 Tot. Element No-Fin Area5.80 m2 Total Element with Fin Area = 16.34 m2 Syngas Temperature out =900 ° F. Tube Thickness = 0.625 in Tube Thickness = 0.0159 m Recycle GasComposition, CO₂= 50% Recycle Gas Comp., H₂O = 50% Annulus Flow Gap =6.000 in Reactor Inner Diameter = 30 in Annulus Diameter = 18.000 in HXtube diameter 4.000 in Hx Tube Length = 80 in Thermal Cond of Inconeltube wall 18.0 W/m-K Feed Water Evap + Superht 117.2 kW Gas in to HX toAnnulus Center out Hx out Strm 309 Strm 318 Center in Strm 324 Strm 311Total units Gas Flow in = 3500 3500 3500 3500 lbs./hr Gas Temp in = 7221350 1600 1850 1332 ° F. Gas Temp out = 722 1350 1275 1850 1332 ° F.Surface Temp in = 100 400 700 ° F. Surface Temp out = 400 700 900 ° F.Gas Temp in = 657 732 871 1010 722 ° C. Gas Temp out = 383 732 691 1010722 ° C. Surface Temp in = 38 204 371 ° C. Surface Temp out = 204 371482 ° C. Gas Ave Temp 793 1005 1054 1283 995 °K Gas Sensible Heat 437 0289 727 kW Gas Density = 0.152 0.118 0.104 0.082 0.110 kg/m3 KinematicViscosity = 0.000400 0.000576 0.000675 0.000886 0.000576 m2/sec ThermalConduct = 0.2690 0.3100 0.3280 0.363 0.3100 W/m-k Flow Cross SectionArea = 0.0730 0.2842 0.1584 0.2842 0.2919 m2 Gas Velocity = 39.846713.1791 26.8259 18.9651 39.8467 m/s Reynolds No. = 75,908 17,435 30,28316,311 52,714 Sq Root Reynolds No. = 276 132 174 128 230 Prandtl No. =0.717 0.736 0.750 0.775 0.736 Cube Root Prandt No = 0.895 0.903 0.9090.919 0.903 Strake Fract Turbulence 0.000 0.130 0.130 0.130 0.000FrOssling No. = 0.800 1.500 1.500 1.500 0.800 Nusselt No. = 197.3 178.8237.2 176.0 165.9 No Fin heat transfer Area = 0.649 3.317 2.487 3.3170.649 m2 No Fin Heat Trans Coef = 69.650 72.757 102.096 83.834 67.473W/m2-K No Fin Heat Flux = 27.02 120.80 119.59 267.41 30.70 504.11 kW

While the inventions have been illustrated and described in detail inthe drawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly certain embodiments have been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

1.-25. (canceled)
 26. A method for high temperature gasification,comprising: flowing a stream of a first hydrocarbon gas from an entranceof a bottom annular plenum region toward an inlet at a bottom of anannular plenum; flowing the stream of the first hydrocarbon gas from thebottom inlet toward a top outlet; heating the flowing first gas alongthe axial length of the annular plenum; flowing the heated gas from thetop outlet to a top inlet of a cylindrical plenum and toward a bottomoutlet; heating the flowing gas along the axial length of thecylindrical plenum; converting the first hydrocarbon gas to a syngas bysaid heating in at least one of the annular or cylindrical plenums; andremoving the syngas from the bottom outlet.
 27. The method of claim 26,further comprising transferring heat from the syngas proximate thebottom outlet to the first hydrocarbon gas in the bottom annular plenumregion.
 28. The method of claim 26, wherein the bottom annular plenumregion includes a plurality of heat transfer fins.
 29. The method ofclaim 26, wherein the annular plenum surrounds the cylindrical plenum.30. The method of claim 29, wherein the bottom annular plenum region isdiscrete from the annular plenum and located below the annular plenumand the cylindrical plenum.
 31. The method of claim 26, wherein saidheating in the annular plenum is by a plurality of resistive heatingelements each extending along substantially the entire axial length ofthe annular plenum.
 32. The method of claim 26, wherein a wall of theannular plenum includes a plurality of aerodynamic strakes protrudinginto the flowpath.
 33. The method of claim 26, further comprisingthermally insulating an outer diameter of the annular plenum.
 34. Amethod for high temperature gasification, comprising: flowing a streamof a first hydrocarbon gas from an inlet at a bottom of an annularplenum toward a top outlet; heating the flowing first gas along theaxial length of the annular plenum; flowing the heated gas from the topoutlet to a top inlet of a cylindrical plenum and toward a bottomoutlet; heating the flowing gas along the axial length of thecylindrical plenum; converting the first hydrocarbon gas to a syngas bysaid heating in at least one of the annular or cylindrical plenums;removing the syngas from the bottom outlet; and flowing the removedsyngas from the bottom outlet over a heat sink; wherein the annularplenum surrounds the cylindrical plenum.
 35. The method of claim 34,further comprising transferring heat from the heat sink to the firsthydrocarbon gas.
 36. The method of claim 35, wherein said transferringis by radiation and convection.
 37. The method of claim 34, wherein saidtransferring transfers heat from the heat sink to the first hydrocarbongas while flowing the stream of the first hydrocarbon gas toward thebottom inlet of the annular plenum.
 38. The method of claim 34, furthercomprising flowing the stream of the first hydrocarbon gas from anentrance of a bottom annular plenum region toward the bottom inlet. 39.The method of claim 38, wherein the heat sink is in thermalcommunication with the bottom annular plenum region.
 40. A method forhigh temperature gasification, comprising: flowing a stream of a firsthydrocarbon gas from an inlet at a bottom of an annular plenum toward atop outlet; heating the flowing first gas along the axial length of theannular plenum using a plurality of substantially linear heatingelements extending along the axial length of the annular plenum; flowingthe heated gas from the top outlet to a top inlet of a cylindricalplenum and toward a bottom outlet; heating the flowing gas along theaxial length of the cylindrical plenum; converting the first hydrocarbongas to a syngas by said heating in at least one of the annular orcylindrical plenums; and removing the syngas from the bottom outlet. 41.The method of claim 40, wherein the annular plenum surrounds thecylindrical plenum.
 42. The method of claim 40, wherein each of theplurality of heating elements are linear in shape, having two opposingends, and further comprising supporting each heating element at only oneend.
 43. The method of claim 42, wherein the plurality of heatingelements are arranged in parallel.
 44. The method of claim 40, whereineach of the plurality of heating elements are discrete and spaced apartfrom each other.
 45. The method of claim 40, wherein each of theplurality of heating elements extends along substantially the entireaxial length of the annular plenum.